The present invention relates to the field of arm rests for use on chairs. More particularly, the invention relates to the field of arm rests which are adjustable to selected heights to provide a more comfortable chair for a user.
Chairs, particularly office chairs, are often designed with the arm rests secured in a fixed position based on the intended use of the chair and the average size of the expected users. However, in an office environment, people of different sizes may spend many hours in a chair. Therefore, it is desirable to have arm rests that are adjustable to match the specific anatomy of a given user. A chair, in particular the arm rests, should be comfortable for people of all sizes and shapes. Similarly, arm rests should be adjustable depending on the varied activities of the user of the chair. For example, a user may desire an arm rest at a first height when working with a pen and paper on a desk, but desire a second height when working with a computer.
Some adjustable arm rests have been disclosed in the prior art. For example, in U.S. Pat. No. 4,951,995 issued to Teppo et. al., a complex arm height adjustment mechanism for a chair is disclosed. A vertical motion translation mechanism interconnects two laterally spaced arm rests. A cable assembly together with a rotatable gear translate movement from a first arm into a corresponding movement in the second arm thereby providing for the synchronized movement of the arm rest assembly. U.S. Pat. No. 4,884,846 issued to Tobler, discloses arm rests with limited height adjustment capabilities. The arm rest is adjusted through the rotation of a carrier element on the arm rest support. The support element is a two part bolt construction with right-hand and left-hand threads coupled together by the carrier element.
While the above-described arm rests have been previously known, there still exists a need for adjustable arm rests that provide reliable operation.